The present invention relates generally to dust collection systems for shop tools. More specifically, the present invention relates to dust collection systems that attach to router tables and allow for the removal of the dust and chips that are generated by high volume, bottom up routing which has become the process of choice for many woodworkers in recent years.
Since the introduction of the router table, users have typically had to cope with the very high volume of flying sawdust particles and wood chips generated by these devices. According to the National Institute for Occupational Safety and Health (NIOSH), wood dust particles are known to cause health problems including eye and skin irritation, allergy, reduced lung function, asthma, and nasal cancer. Further, wood dust is known to be a human carcinogen. As a result, in order to protect themselves workers have undertaken the cutting of wood outdoors, wearing masks, building makeshift containers, enclosing the base of the router table or building plastic enclosures around their work area. One difficulty that arises is that cutting wood outdoors is often limited by poor weather conditions. As a result, work schedules are often disrupted when conditions do not permit cutting outdoors. Additionally, dust particles and wood chips that drop to the ground are frequently tracked into living areas of the home and get lodged in carpets and in furnishings where they can create an unhealthy environment. Additionally, since routers are inverted when connected to the underside of these router tables, the sawdust drops directly into the router motor often causing premature motor burnout and costly replacement.
In the prior art, there are a number of products that have been designed to collect sawdust generated by routers such as U.S. Pat. No. 3,022,806 (Johnson) which discloses a guard that surrounds the dust escape openings of a “conventional” router and includes a dust collection cavity with a dust port which can be attached to a vacuum hose. However, a wide variety of new routers have replaced the “conventional” router and most have unique designs that would preclude the attachment of the Johnson device. Further, the Johnston device causes the mechanism for raising and lowering of the cutting tool to become fixed and no longer adjustable, taking away the ability to cut at different heights and depths with the same cutting tool.
U.S. Pat. No. 3,837,383 (Ko) provides a tubular or cylindrical collecting device that includes a tangentially arranged suction apparatus for creating a partial vacuum within the device used to remove dust generated by contact between a tool and a work piece. This apparatus may be adaptable to some routers but also would not allow for adjustment of the cutting tool, would not collect dust from the table surface and does not protect the router motor from burnout.
U.S. Pat. No. 4,051,880 (Hestily) includes a portable electric router having a dust chamber formed below a motor mounted to a base having two handles one of which is in communication with the chamber that in turn is connected to a blower and dust bag fixed to the top of the motor. The Hestily device is for top down routing and is evidently adaptable to a router table for bottom up routing but in such an arrangement it would not collect dust from the table surface and does not protect the router motor from burnout. It is costly to produce and is not adaptable to existing routers. Wood workers would not be able to use their existing routers.
U.S. Pat. No. 4,409,699 (Moorehouse) consists of a base attached to any type of power tool that makes by products such as wood chips, etc. The base is provided with a neck and a hose is connected into the neck, which in turn can be attached to a vacuum system. A slidable platform includes an aperture and an air chamber that allows the by by-products to travel into the neck and to a vacuum system. A post is connected to the base and another to the platform and is biased with a spring. While it appears useful for top down routing it is not adaptable for bottom up routing, as the air chamber of the assembly would not allow for a flush fit of a router to the underside of a router table.
U.S. Pat. No. 4,738,571 (Olson et al.) consists of a base with a dust port, a sub-base having a large cavity attached to the base which both in symmetry attach to a “conventional” router. While this apparatus appears to be attachable to the underside of a router table, it appears that the small hole in the base will limit the depth of some cuts, as collets of routers will not pass through it. In addition, provisions are not evident for the large variety of different dimension router bases that are currently in production. Many new routers are attached to lift mechanisms designed to allow cuts at very close tolerances and this apparatus would require a major re-design to accommodate such lifts. In addition, the cited apparatus has no provision for simultaneously collecting sawdust and chips from both top and bottom surfaces of a router table.
U.S. Pat. No. 4,750,536 (Grisley) is a waste attachment for a router which is a hollow arm which pivots as the work piece passes through the cutting tool and which guides sawdust and chips to a vacuum port. This invention by its design is for hand held routing and not attachable to either top or bottom of a router table.
U.S. Pat. No. 5,396,937 (Clausen) is a router table for supporting a normally hand held router which enables precise angular cuts and has a hollow housing with a dust port for connecting to a vacuum. The housing is designed to collect dust and is located on the top of the table and behind a fence that guides the work piece. This invention appears capable of collecting sawdust and chips on end cuts and not on dado cuts. Further, it does not have any means for collecting the dust that falls through the bottom of the router table nor does it protect the router motor from accumulating dust and motor burn out.
U.S. Pat. No. 5,503,203 (Stornetta) is a cylindrical housing or “dust hood” for a portable router which surrounds the dust escape openings on either side of a cutting tool. A dust port is attached to the housing and is attachable to a vacuum source. The invention also includes a sub-base that is attached to the bottom plate of the dust router. It is not likely that a router having this attachment would be attachable to the underside of a router table but should it be attachable there is no provision for collecting dust on the top surface of the router table nor is there any means for protecting the router motor from accumulating dust and motor burn out.
U.S. Pat. No. 5,553,644 (Adams) comprises a fence support of hollow rectangular configuration defining a chamber that is connectable to a vacuum source for removal of dust and chips produced by a cutting tool such as a router. This invention appears to be adaptable to a variety of router tables and appears to be capable of collecting sawdust and chips from the top of the table surface. It does not have any means for collecting dust that falls through the bottom of the router table nor does it protect the router motor from accumulating dust and motor burn out.
U.S. Pat. No. 5,584,620 (Blickhan et al.) provides a router with a cutter head containing the drive motor so that the cutter head is held in a displaceable manner at guide columns which are secured to a base plate which has a suction intake channel which surrounds the central opening. The intake channel is connected to a suction extraction channel, which is connectable to a vacuum source. It is not likely that this router would be attachable to the underside of a router table but should it be attachable there is no provision for collecting dust on the top surface of the router table nor is there any means for collecting dust which falls through the bottom of the router table or for protecting the router motor from accumulating dust and motor burn out.
U.S. Pat. No. 5,611,378 (Brazell) is router table assembly with a tiltable table subassembly that allows variation in positioning the router axis and includes a router mounting plate specifically designed for the table and a unique table design. The table and mounting plate have connecting vacuum channels with a tube connectable to a vacuum source. The design of the channels is such that slivers of wood are likely to clog the dust and chip escape route and render the system inoperable. Aside from this issue, the channels do not appear to be of sufficient height to accommodate many of the mid and larger size cutting tools that are currently on the market. As such, much of the flying dust and chips would not be collected by the system but would fly either above or below the cutting tool. It appears that it may not protect the motor from accumulating dust and motor burn out. An additional limitation is the fact that the dust collection system is built into the table and is not adaptable to the many other router tables currently on the market—it is not a universal fit.
U.S. Pat. No. 5,993,124 (Cooper) is a system that includes a router sub-base adapted for connection to a router. The system includes lower and upper vacuum flow paths configured to evacuate dust from within and beneath the router sub-base. This system is designed for cutting edges of work pieces by hand and not for use with a router table and is not attachable to a router table. The design is such that dust and chips are collected to the rear side of the router away from the cutting tool with dust and chips likely escaping from the front side of the cutting operation. There is no provision to collect dust and chips coming from this area. In addition, with this system installed on a router, dust and chip collection will not be possible for dado types of cuts and it is not a universal fit for routers.
U.S. Pat. No. 7,290,967 (Steimel et al.) is a device attachable to a router that consists of rotatable dust trap able to be connected with a footplate of a router and arranged to the side of the routing tool underneath the footplate and such dust trap being open toward the routing tool. This device is designed for cutting edges of work pieces by hand and not for use with a router table and is not attachable to a router table. The design is such that dust and chips are collected to the rear side of the router away from the cutting tool with dust and chips likely escaping from the front side of the cutting operation. There is no provision to collect dust and chips coming from this area. In addition, with this system installed on a router, dust and chip collection will not be possible for dado types of cuts nor will the use of an adjustable fence be possible without removing the dust trap and rendering dust and chip collection impossible.
Another device in the marketplace is a dust collector for a router table that consists of a dust port which attaches to a specially designed insert and which fits into a router base. When a vacuum source attaches to the dust port, dust and chips can be evacuated from under the router when doing dado cuts. This specially designed insert is for a proprietary router base and is not a universal fit. The dust port is a circular cup with a narrow rectangular port and is made of a hard plastic material. There is no provision for collecting dust and chips from the top surface of router tables when doing end cuts, it's only function is for collecting dust when making dado cuts. In addition, while similar in design to the present invention, the dust port is not a universal fit and being made of hard plastic will require removal when router collets are adjusted in height to accommodate different size cuts. The contour of the inner surface of the dust port is flat on the bottom surface and flat on the side surface, which will likely contribute to clogging created by chips collecting in the corners of the flat surfaces.
Accordingly, there is a need to provide a dust collector that is adaptable to any router, router table and/or any router table insert and which is attachable to router table fences equipped with dust ports. There is a further need for a dust collector which collects sawdust and chips from both the top and bottom surfaces of the router table and which collects dust and chips that fall down and away from the cutting tool and simultaneously collects dust and chips that fly up and away from the cutting tool wile also preventing dust and chip accumulation in router motors thereby maintaining router motor cooling efficiency and preventing premature motor burn out.